Compounds having antagonism to muscarinic receptors are known to cause bronchodilation, gastrointestinal hypanakinesis, gastric hyposecretion, dry mouth, mydriasis, suppression of bladder contraction, hypohidrosis, tachycardia and the like [cf. Seitai no Kagaku (biochemistry), Vol. 42, p. 381 (1991)].
There are three subtypes of muscarinic receptors: M.sub.1 receptors are present mainly in the brain, M.sub.2 receptors, mainly in the heart, and M.sub.3 receptors, on smooth muscles and glandular tissues. While a large number of compounds having antagonism to muscarinic receptors became known to date, those known compounds non-selectively antagonize the three subtypes of muscarinic receptors. Hence, attempts to use these compounds as therapeutic or prophylactic agents for diseases of the respiratory system have caused undesirable side effects such as tachycardia, dry mouth, nausea and mydriasis. In particular, side effects associated with the heart such as tachycardia induced by M.sub.2 receptors pose problems, and their improvement has been in strong demand.